Understanding the anatomy of the ossicles on the axial scan is important for the head and neck radiologist. With the colours switched off see if you can identify the ossicles. Switch the colours on to see if you are right.

The Ossicles

Note the malleus (red) lies anterior to the incus (blue). The malleo-incudal joint is synovial and lies in the epitymapum. The stapes (green) is small and lies slightly obliquely, so it may not be clearly seen in the axial plane on all scans. It is also a very thin structure.

Practical Tip

You should be able to identify the handle of the malleus and the long process of the incus as two dots one in front of the other on all axial scans. Absence of one dot indicates an ossicular erosion – most commonly affecting the long process of the incus because of its poor blood supply.